What Folders to Choose When Manually Backing Up Your Mac

By Jim Tanous

Aug 8th, 2013 1:33 PM EDT

Question:

Jurgen writes: I use CrashPlan to back up specific data for extra "offsite" protection, but I've been having trouble with Time Machine for my local, full system backup and I'd like to try backing up my entire Mac using CrashPlan's local backup feature. Time Machine automatically handles which folders and data to back up to ensure that my system is protected (when it works, that is), but I'll need to do that manually with CrashPlan.

So, if I want a full system backup with CrashPlan that offers the same level of protection as a local Time Machine backup, which files and folders should I tell CrashPlan to back up?

Answer:

These suggestions apply to virtually any service or software that allows for selective backup.

When choosing what to backup manually, first and most importantly look to the Users folder, located by default at Macintosh HD/Users/. This will back up your user account, along with any other accounts on the Mac, plus any shared data. Each user account contains your Desktop files, documents, downloads, videos, music, and pictures. If you have more than one user on your Mac, and you’re only interested in backing up your own data, just go one level deeper and select your user account from within the Users folder.

Another location you may wish to back up is the system level Library folder, located at Macintosh HD/Library/. While all of your personal preferences and application support data should be in your user Library folder, which is backed up in the steps above, some applications, such as Microsoft Office, install various items to the system Library folder. You’d probably be fine with not backing this folder up, but if you’re looking for a complete backup solution that lets you resume work immediately after restoring your data, it’s a good idea to grab this folder as well.

The Applications folder, at Macintosh HD/Applications, is also prime target for backup. The Mac App Store and downloadable software purchases have made it relatively easy to reinstall lost applications after a hard drive crash or data loss, but it’s still a time-consuming process even with a fast network connection. By backing up this folder locally, you can quickly restore all of you existing applications without having to re-download or reinstall them one-by-one.

Note, however, that some applications with strong DRM (digital rights management), may require that you re-enter your product key after restoring them from backup. Examples of such apps include Microsoft Office and Adobe Creative Suite products.

All of the above recommendations assume that you’ve used the default locations for your data. If you’ve instead saved data to random folders outside of your User folder, you’ll need to check to make sure these get backed up as well. If you don’t see any files in Macintosh HD/Users/[user]/Documents/, for example, open your commonly used applications and trace your files back to their actual locations.

What to Exclude

If you want complete backup coverage and you have a large enough storage drive, just back up everything. If you’re backup space is limited, however, consider excluding the following items:

Macintosh HD/Users/[user]/Library/Mobile Documents - this is where Apple stores local copies of your iCloud data. If you lose it due to a hard drive failure, all of the data will be automatically downloaded again once you restore your Mac and log in with iCloud.

Macintosh HD/Users/[user]/Library/Containers/com.apple.mail/Data/Library/Mail Downloads - when you view an email attachment in Mail, it gets stored to this temporary location until you save it to your drive or delete the message. Just as above with iCloud, if you lose the contents of this folder, they’ll automatically re-download when you set your email account back up after restoring.

Macintosh HD/Users/[user]/Music/iTunes/iTunes Media/Movies (and TV Shows) - if your movies and TV show folders are filled exclusively with purchased iTunes content, then you don’t have to worry about backing them up. These can be huge, multi-gigabyte files that take up a lot of space, and you’ll always be able to download them again from Apple at any time. Of course, if you have non-iTunes content in these folders, such as files sourced from home videos or ripped DVDs, you’ll want to make sure they’re backed up along with the rest of your data.

Cloud Service Folders - services like Dropbox, SugarSync, and SkyDrive can be configured to store data on your local Mac. Although it’s good to have at least one backup of the data stored on these services (in case their data centers are ever destroyed), most users will be safe skipping these folders in their backup. Once you’ve restored your Mac, simply reconnect to these services and re-download (or re-sync) your data.

Virtual Machines - users who run virtualization software like Parallels Desktop or VMware Fusion likely have at least one huge virtual machine file on their Mac. If you use a VM for actual work, such as running Windows-only accounting software, then you’ll definitely want to back these files up. But if you only use them for testing, and the machines hold no crucial data, then you can safely exclude them if you choose. You’ll have to go through the process of recreating the machines and reinstalling your virtual OS, but it might be worth it for some users to save 30 or 40 GB on their backup drive.

Other Large Files - every Mac user is different, and there’s no way to anticipate each user’s needs. It’s therefore recommended that all users also browse their Macs for large files that might be good candidates for exclusion. One of the best ways to do this is to use the excellent free tool OmniDiskSweeper. If you run the app as a root user, it can reveal hidden sources of data that take up large amounts of space but really aren’t that important, letting each user create a custom backup plan.

Whichever steps, methods, or software you choose, just make sure that you back up your data, preferably using the “3–2–1” strategy: 3 total copies of each important file (the original plus two backups), stored on 2 different types of media (such as hard drives and optical disks), with 1 copy stored offsite (either physically offsite, such as keeping an external hard drive at a friend’s house, or in the cloud).